Torching witnessed Sunday on the Lone Star Fire in Yellowstone National Park/NPS

Rocky Mountain, Sequoia, Saguaro, Yellowstone, and Yosemite national parks all were dealing with wildfires Monday, as was Point Reyes National Seashore, though a potent cold front sweeping down from Canada should bring some relief for firefighters in Rocky Mountain and Yellowstone.

"Winter will make an early arrival in northern Colorado tonight and Tuesday as a strong cold front from central Canada will bring much colder temperatures as well as accumulating snow to the region," the National Weather Service said Monday evening. "Temperatures will drop quickly behind a cold front this evening with snow starting shortly after midnight over the higher mountains and foothills."

At Yellowstone, the Lone Star Fire 3 miles south of the Old Faithful complex had grown to more than 3,000 acres, and was burning in stands of mature, unburned forest of spruce, fir, and lodgepole pine. Fifty-two firefighters were monitoring the blaze that was sparked by lightning on August 22, and fire engines were stationed near the Old Faithful Inn. The fire also had moved to within a mile of the Cove Cabin, a backcountry ranger outpost on the north shore of Shoshone Lake.

The park was told to expect rain and snow Monday night, with low temperatures in the teens.

At Yosemite, while the nearly 80,000-acre Creek Fire was outside the park, crews were taking protective steps at the Mariposa Grove, including wrapping the historic Mariposa Grove Museum in fire-protective material.

The Mariposa Grove Museum was wrapped in fire protective material as a precaution in case the Creek Fire moved into the park/NPS

“Yosemite’s fire personnel are taking preventative measures now to protect critical park resources and infrastructure,” said Dan Buckley, Yosemite fire management officer. “By taking these preventative measures now we will be able to more effectively allocate fire resources in response to the Creek Fire.”

At Rocky Mountain, the 89,000-acre Cameron Peak Fire had inched into the northwestern corner of the park, where it was burning in Poudre Canyon and within the Cascade and Hauges creeks drainages. The approaching snowstorm, though, should greatly help firefighters knock down the fire.

"A strong cold front will move through between 1800-2100 (6 p.m.-9 p.m.) Monday evening with lows overnight dropping to around 20 degrees," read the fire briefing Monday morning. "Snow, heavy at times, will begin in earnest after midnight with northeast winds gusting to 40 mph. This will create near-blizzard conditions at times through at least Tuesday morning.

"The heaviest accumulating snow will end by Tuesday afternoon with some light snow showers continuing into Tuesday night. Lows Tuesday night will drop into the teens with single digits possible if it clears out. Expect 6-12 inches of snow across the entire fire area with the highest totals falling above 9,000 feet."

Two fires were burning in Sequoia: The 990-acre Rattlesnake Fire, and the 550-acre Moraine Fire. The Moraine Fire was located within the Sequoia-Kings Canyon Wilderness, southeast of Cedar Grove, Kings Canyon National Park, and was 65 percent contained. The Rattlesnake Fire was burning in the same wilderness area and was being monitored by air.

Saguaro National Park's Spud Rock Fire covered 760 acres in the Saguaro Wilderness, while the Mica Bowl Fire, also in the wilderness area, covered just 26 acres.

At Point Reyes National Seashore, the Woodward Fire was approaching 5,000 acres in size, and was 95 percent contained.